![]() ![]() Moulding was performed using green stick tracing compound (Fig 3). BorderĢ- Acrylic resin tray attached to metal framework The cast metal framework was tried intra-orally for accuracy of fit and once this was done, an acrylic resin custom made trays were fabricated to the mandibular framework (Fig 2.). Investing and casting procedures were performed in the laboratory and the completed framework was checked to ensure that it fits the casts accurately (Fig 1). Master casts were obtained and design finalized. Mouth preparation was done intraorally and final impressions of both the arches were recorded using medium bodied addition cured silicone (Zhermack Elite Monophase) using custom made trays. Mandibular study casts were placed on a stage of a dental surveyor and surveying was carried out after which the design of the cast metal framework was finalized. Maxillary and mandibular impressions were obtained using irreversible hydrocolloid (Cavex CA37?, Holland BV) and upper and lower study casts were obtained. ![]() A step by step procedure is outlined with reference to various clinical and laboratory stages during the treatment: The patient decided to pursue the treatment plan which included the fabrication of a lower CPD. Option of implant retained fixed partial dentures was given to the patient but the patient could not afford the expense of the treatment. No further signs of abnormalities were detected during intra-oral and extra-oral examination and it was decided that a new cast partial denture (CPD) is provided to the patient using the alteredcast technique once tissue healing is adequate. The denture had inadequate base extensions and poor tissue adaptation due to which there were signs of minor trauma to the soft tissue covering the crest of the alveolar ridge. The patient was wearing an acrylic partial denture which was loose and ill fitting. CASE REPORTĪ 53 year old medically stable female patient attended the outpatient department of ZiauddinCollege of dentistry complaining of missing posterior teeth in the lower arch. The following paper outlines a quick and easy technique for constructing an altered cast for an RPD. Other benefits include reduction of the number of post operative visits, preservation of the residual ridges and decreasing the food impaction. It offers several advantages which include maximum stability, minimal stress on abutment teeth, and more predictable occlusion (3). Also known as the corrected-cast technique (3) the technique requires an additional step for both the dentist and the dental technician. Support from the residual alveolar ridge as described by Carr and Brown (1) will depend on several factors which include the quality of the residual alveolar ridge and its contour, extent of the ridge covered by the RPD, the accuracy of the impression, fitting accuracy of the denture, RPD design and the total occlusal load applied during function.Īn altered cast impression procedure to improve the support of distal extension removable partial dentures is widely taught, but not often used in dental practice (2). The tooth supported RPDs have an advantage of presence of a direct retainer whereas this is lacking in the prosthesis fabricated over distal extension bases. These dentures only have partial support from teeth as their bases may be the extensions covering the ridge distal to the last abutment tooth. INTRODUCTIONĭistal extension removable partial denture (RPD) depends largely on the residual alveolar ridge for support, stability and retention. Altered Cast Technique: Improving Tissue Support for the Distal Extension Bases. HOW TO CITE: Rashid H, Vohra FA, Shahzad A. KEYWORDS: Distal extension bases, Stability, Addition Cured Silicones, Altered Cast Technique, Corrected Cast Technique The aim of this case report is to portray an approach of recording a minimal tissue displacing altered cast impression using addition cured silicone material. Oral tissues that have been displaced during the impression procedure attempt to regain the anatomic form and they may get inflamed if the denture base does not permit them to do so. The technique is relatively simple but requires increased chair-side time and laboratory cost. Altered cast impression technique is commonly used for the mandibular distal extension partially edentulous arches. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |